Newman and Girvan [1]} proposed the modularity as a concept for a network partitioning,
\(m = \frac{1}{2L}\cdot \sum \limits _{i=1}^{N} \sum \limits _{j=1}^{N} \left(a_{ij}-\frac{d_{i}\cdot d_{j}}{2L}\right) \cdot \mathbf {1}_{\lbrace i\, \text{and}\, j \,\in \text{ same cluster}\rbrace },\) 
